Here is an in-room measurement of my 8351B pushing almost 100db (
other measurements here too):
View attachment 125214
However if you push it any further, Genelec’s DSP will automatically engage the limiter and it won’t get any louder. I actually like this: I’d rather see a warning light flash and suggest to me I need a subwoofer, than for a speaker to start distorting.
Genelecs are basically impossible to distort, because their on-board software is pretty aggressive at ensuring they aren’t pushed anywhere near their mechanics limits (and I suspect this also increases their reliability too). In contrast, my Neumann KH320’s would allow you to push them to around 100% THD in bass frequencies before the limiter engages, however the distortion never sounds particularly bad even when it is audible (perhaps due to the sealed design). Still, I prefer Genelec’s limiter approach.
In my (not exactly controlled scientific) tests, Genelec 8351B always kept distortion impressively low at all times until the limiter engages. Bass distortion is similar to the Revel Salon2 in the linked thread above (which is extremely good, actually better than any subwoofers I’ve had), and keeps up in every respect until 95-100db, where the Genelec limiter starts to kick in (only for bass frequencies; for mids and treble the Genelec will go as loud as any human would want) whereas of course the Revel (with 3x 8” woofers) isn’t anywhere near its limits.
The 8351B is still a comparably “small” speaker though, and while its SPL capabilities are extremely impressive for the size, you can’t defy physics. If you want high SPL down to 20hz in a large room you’re going to need a subwoofer or four.